Transmission gearing for power plants



Sept. 9, F c. MARCHANT 2,609,707

' TRANSMISSION GEARING FOR POWER PLANTS Filed April 9, 1947 I s She-ts-Shwt 1' P 9, 1952 F. c. 1. MARCHANT 2,609,707

TRANSMISSION GEARING FOR POWER PLANTS Filed April 9 1947 5 Shets-Sheet 3 V r 1 I g r I 50 V 2 Q S l 1' Z s l I J II-l===::n .3

51 I I g I M 3 I J I I 1 I 1L Ill 56 I 55 I I Patented Sept. 9, 1952 Francis Charles Ivor Marchant, Bristol, England, assignor to The Bristol Aeroplane Company Limited, Bristol, England, a British company Application April 9, 1947, Serial No. 740,498 In Great Britain March 19,1946

Section 1, Public Law 690, August 8, 1946 Patent expires March 19, 1966 This invention relates to power plants, particularly for aircraft, and has for its object to provide an improved construction and arrangement enabling two or more engines to be used to drive two or more output shafts-Such as carry airscrews-in various combinations, and in particular relates to an improved construction of transmission gearing coupling the engines and the output shafts. By the term engines is to be understood internal-combustion engines of the reciprocating type or gas-turbine power units.

According to the present invention there is provided in a power plant the combination with two or more engines and counter-rotating output ,3 Claims. (01. 74-665) shafts therefor, of a driving connection between the engines andthe shafts which comprises afirst reduction gear for each engine to drive a shaft common thereto and a second gearing disposed between said shaft and each output shaft to effect a further speed reduction and rotation of the shafts in opposite directions.

Preferably there is associated with each engine means for independently coupling it to, and uncoupling it from, said first gearing, said means being actuated either at the direction of the operator or automatically under predetermined conditions.

The long axes of the engines may be disposed parallel to each other and said output shafts placed in front of the units with their common axis of rotation between and parallel to said long axes, said connecting shaft'being co-axial with the common axis of the output shafts and extending from-the first to the second gearing aforesaid.

Preferably the common shaft is connected to each of the first and second gearings by metans of a flexible joint.

A specific embodiment of the present invention will now be described, by way of example, as applied to a power plant for driving counterrotating airscrews of an aeroplane. The description will be made with reference to the accompanying drawings whereof:

Figure lis a plan view of the power plant showing it installed in the wing of the aeroplane,

Figure 2 is a sectional plan View of the first reduction gearing for one engine of the power plant, and

Figure 3 is a sectional plan view of the second reduction gearing.

Referring to Figure l: the power plant, which is generally indicated by the reference numeral 5, comprises a pair of engines or power units 6 2 the long axes of which extend chordwise of th wing 1 within which the plant 5 is buried. Each unit 6 comprises an air intake 8, a compressor 9, a plurality of combustion chambers ID, a gas turbine II and a jet pipe 12. Each turbine H has a pair of independently rotating rotorslnot shown). One rotor being provided to drive the compressor 9 and the other the shaft I3 Air enters the intake 8 at the leading-edge of the wing 1 and the exhaust gases from the turbine H are ejected through the jet pipes 12 at the trailing edge.

There is provided between each unit 6 and a pair of counter-rotating airscrews M, a driving connection comprising a first reduction gearing, generally indicated at 15, which connects each unit with a common transmission shaft [6 and a second reduction gearing H which connects the common shaft to the airscrews [4. As is clear from Figure 1 the axis of the common shaft I6 is parallel with the long axis of the units and lies betweenthem. The shaft It extends chordwise of the wing I from the first reduction gearings I5 to the'second gearing l1.

The first reduction gearings. l5 each comprises a pinion l8 (Figure 2) connected to the output shaft l'3 of unit 6, a gear wheel l9 connected to the common intermediate shaft [6 and an idler which meshes with the pinion l8 and the gear 19. For convenience in construction the pinion I3 and the idler 20 are formed as two separate gears. The gearing is designed to give a reduction in speed from that of the output shaft [3 of each power unit. From this description it will be appreciated that the wheel I9 is common-to the two reduction gearings l5.

The pinion 18, as shown in Figure 2, is mounted on a shaft 2| formed with one element of a clutch which is generally indicated by the reference numeral 22. The other element of the clutch comprises a sleeve 23 mounted by splines on shaft l3 for reciprocation thereon. The movements of the sleeve 23 are effected by an hydraulic'motor 24 the ram 25 of which is coupled (through roller bearing 26) to thesleeve 23 so that when pressure fluid is fed to the motor 24 by pipe 21 the clutch is engaged and when the pressure fluid is fed by pipe 28 to the motor the clutch is disengaged. The clutch 22 may be operated' in this way at the will of the pilot or flight engmeer.

The second gearing l1 comprises an input shaft 2Q driven by the shaft it, a pinion 30 mounted thereon a plurality of layshafts disposed parallel with and around the input shaft and two sets of gears one associated with the forward airscrew [4a and the other with the rear airscrew Mb. In the particular construction being described a total of five layshafts '31 :are provided, each of which carries a gear 32 meshing with the pinion 30. Each layshaft 3| carries another pinion 33 which meshes with a gear 34 lying within the layshafts 3| and carried by the front vairscrew shaft 141a. Each layshaft also carries a gear 35 which meshes with an annular gear 36 carried by the .rear airscrew shaft Mb.

The second gearing I! provides a furtherreduction in speed as between the shaft 16 and the airscrews l4 and also transmits drive to the .-air-.

screws so that they rotate in opposite directions. The gear wheel l9 (Figure 2), .is carried by a shaft 31 which is supported in bearings .38 and is in continuous driving engagement with the com- I mon shaft I6 by a toothed or splined connection generally indicated by the reference numeral 39. --.J11e shaft is supported from shaft 97 by a ball-- end-socket joint 49 so that limited lateral movements of the shaft 1&6 are permitted relatively to powerplant. For the same purpose the common shaft l connected with the input-shaft 129 .of gearing .17 by a toothed connection 39 and ahall-and-socket :joint 40, as shown in Figure '3. ifflhis form of connection enables the common shaft I26 to be readily disconnected from the shafts?!) :and 37 during removal of the gearing l7 and shaft I 6.

The shaft 31 carries gearing 4! by which nuxiliariea'such as'fuel pumps, oil pumps, yacupumps, compressors, generators .and so on, for therpower plant or aeroplane :are driven.

' .Itisa particular advantage of the present inwentinn that the reduction in :speed between each power :unit tand. the airscrews M is performedin awostages since the reduction called for is considenalblenmenjthe power units comprise gas tur-- ihinea;

.nlthoughzthe invention has been described as zapplied to .a "power plant for :an aeroplane it is not so limited and may be installed in :boats, land wehicles :(such as locomotives) or .be used in sta- :tionary installations I1, lllransm'msion gearing :for :multi-engine power plants comprising a pair of parallel engine aandntermediate shaft common to said engine shafts and disposed parallel therewith, .a

reduction gearing ,dr-ivingly connecting the enginephafts to said common shaft, means for independently coupling each engine shaft to, and

uneoupling from, said first reduction gearing, a pair of oppositely rotating output shafts, said. output shafts being coaxially nested one within .wthe other and :lying between and parallel with said engine shafts, :the intermediate shaft being coaxial with the output shafts, and a second -,gearing drivingly connecting the cominon shaft to the output shafts, saideommon shaft extending from the .first to the second gearing and be- .ing connected -to each of the first and second :gearings :by means of :a fiexi-blejoint said second gearing effecting -a further speed reduction and Y 4 also rotation of the output shafts in opposite directions.

2. Transmission gearing I for multi-engine power plants comprising apair of parallel engine shafts, an intermediate shaft common to said engine shafts and disposed parallel therewith, a reduction gearing drivingly connecting each of the engine shafts to said common shaft, means associated with each engine shaft for independently coupling each shaft to, and uncoupling 'it from, the reduction gearing associated therewith, a pair of output shafts and a second gearing drivingly connecting the common shaft to the output shafts, said second gearing effecting a further speed reduction and also rotation of the -,outputshafts in opposite directions, said second reduction gearing comprising a single input shaft driven by the common shaft, said output shafts being coaxial with the input shaft, a plurality of layshafts disposed around said shafts, a driving connection from the input shafts to the layshafts and from the latter to each ,outputshaft, said driving connection comprising a pair of axiallyspacedlaysha-ft pinions one of which meshes with a wheel lying within the pinions and carried .by the inner output shaft and the other of which meshes with an internally toothed gear carried by the other output shaft.

3. Transmission gearing for multi-engine power plants comprising a pair of parallel engine shafts, an intermediate shaft common .to said engine shafts and disposed parallel therewith, a first reduction gearing for each of said engine shafts driving-1y connecting said engine shafts to said common shaft, each of said reduction gear-'- ings including a clutch .and means :for operating said clutches; independently of each other, so that each-engine shaft can be independently coupledto or uncoupled from its reduction gearing. .a pair of coaxially nested output shafts lying between the engine shafts and parallel therewith, and a second gearing driyingly connecting the ommon shaft to the output shafts, said second REFERENCES CITED The following references are of record in the :file nf this patent:

UNITED "STATES PATENTS Number Name Date 1,253,710 Ogawa 1J an. 15, 1918 1,680,672 Fawick Aug. 14, .1928 1,902,374 Pirinoli Mar. ,21, 1933 1,961,953 Bauer r June 5, 1934 2,180,599 Menasco ,Nov. 21, 1939 2,297,400 .Friedrich Sept. 29, 1942 2,305,373 ,Adamson Dec. 15, 1942 2,305,454 Nallinger ,et 8.1., Dec. 15, 1942 2,396,745 Nallinger et al. Mar. 19., 1946 2 427,135 Guier ,Sept. 9, 1947 2,451,598 Wilson Oct. 19, 1948 2,496,857 Cronstadt et a1. Feb. 7, 1950 2,513,286 

